import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;

public class Test1 {
    public static void main(String[] args) {
        ExecutorService service1 = Executors.newCachedThreadPool();
        ExecutorService service2 = Executors.newFixedThreadPool(3);
        ExecutorService service3 = Executors.newSingleThreadExecutor();
        ExecutorService service4 = Executors.newScheduledThreadPool(3 );
    }
}
